The present invention relates to a light irradiating apparatus and a light irradiating method and, more particularly, to a light irradiating apparatus and a light irradiating method that are for suitable use in helping recovery from a jetlag syndrome for example.
Usually, a travel by jetliner for example over regions having time differences of not shorter than four to five hours may cause a so-called jetlag, a temporary mental and/or physical disorder. This disorder often includes insomnia, drowsiness, fatigue, and/or anorexia.
Some people suffering from sleep disorder, depression, Alzheimer's disease, or the like are found having abnormal biorhythms, namely, a widely-defined jetlag. It is known that the symptoms of jetlag are improved by putting the biorhythm into order.
The period of the human biological clock is said to be around 25 hours, causing a difference of about one hour from the 24 hours in which the earth makes one rotation. This time lag may be reset by the exposition to the sunlight or other lights of high illumination, synchronizing the human biological clock with the earth's daily rotation.
Thus, the irradiation of high illumination puts the human biorhythm into order. Therefore, for a method of putting the human biorhythm into order, optical treatments are used in which a light irradiating apparatus for irradiating a light having as high an illumination as the sunlight irradiates the light to a client with a timing and a duration of irradiation in accordance with the degree of the client's biorhythm disorder.
With some light irradiating apparatuses used for optical treatment, the light irradiating block for irradiating light is fixed in front of the eyes of the wearer of a light irradiating apparatus with a head band (refer to Japanese Patent Laid-open No. Hei 9-213101) or the light source is arranged on the lens frame of the eye glass (refer to Japanese Patent Laid-open No. 2002-350790) in order to achieve small-sized apparatuses.